Monoesters of tetrahydrofuran glycol



United States Patent 3,014,927 MONOESTERS F TETRAHYDROFURAN GLYCOL JohnD. Garber, Westfield,-Robert E. Jones, Rahway,

and Samuel A. Robinson, Scotch Plains, N.J., assignors to Merck 8.: Co.,Inc., Rahway, NJ., a corporation of New Jersey No Drawing. Filed Oct. 5,1960, Ser. No. 60,553 6 Claims. (Cl. 260 -3474) S I RCOzCHr-LO CHzOH inwhich R represents an aliphatic radical having from 1 to 18 carbonatoms, and by the formulae:

in which it varies from 1 to 10.

The saturated monoesters of this invention are useful as selectivesolvents as in the separation of aromatic hydrocarbons from naphthenicor aliphatic hydrocarbons. For example, aqueous solutions of themonoacetate of 2,5-tetrahydrofuran dimethanol will eflect the separationof toluene from N-heptane. By varying the chain lengths of themonoesters of the 2,S-tetrahydrofurandimethanol it is possible to varythe solubility in water and hydrocarbons and hence the solventproperties thereof as compared to the parent glycol. In addition, thehigher alkyl monoesters of 2,5-tetrahydrofurandimethanol such as2,5-tetrahydrofurandimethanol monolaurate and2,5-tetrahydrofurandimethanol monooleate are useful as wetting agents.Also, the sodium sulfate esters of the higher alkyl monoesters of the2,S-tetrahydrofurandimethanol are valuable wetting agents and aretherefore useful in wetting agent compositions. The higher alkyl estersof 2,S-tetrahydrofurandimethanol such as 2,5-tetrahydrofurandimethanolmonolaurate show moderate corrosion inhibition properties for carbonsteel. Thus, a sample of carbon steel, when exposed to an environment ofbrine, will corrode to a much lesser extent if the brine contains ahigher alkyl ester 'of 2,5-tetrahydrofurandimethanol.

The unsaturated monoesters are valuable intermediates for the productionof the saturated monoesters of this invention.

In producing the compounds of this invention, hydroxymethyl furfural maybe first converted to unsaturated monoesters. This is done by reactinghydroxymethyl furfural with an acid anhydride or an acyl halide in thepresence of a catalyst such as pyridine. For example, to make bis HMFadipate, hydroxymethyl furfur'al is reacted with adipoyl chloride in thepresence of pyridine at a temperature of about 30 C. The reactiontemperature may vary from 30 C. up to about 50 C. when an acy'l halideis used, and from 80 C. up to 100 C.

r" ce when an organic acid anhydride is used. The resulting monoestersare then subjected to hydrogenation to form the monoesters of2,5-tetrahydrofurandimethanol. The hydrogenation is preferably carriedout in the presence of a catalyst such as Raney nickel at a temperaturein the range of from about C. up to about 200 C. and a pressure of fromabout 100 p.s.i. up to about 1000 p.s.i. Examples of monoesters of HMFused are HMF acetate, propionate, butyrate and hexanoate derived fromtheir monobasic acids and HMF succinate, adipate and sebacate derivedfrom their dibasic acids. These compounds are formed by reacting suchcompounds as propionic anhydride, butyric anhydride, hexanoic anhydride,succinoyl chloride, adipoyl chloride or succinic anhydride withhydroxymethyl furfural.

The saturated monoesters of this invention may alternatively be preparedby reacting an excess quantity of 2,S-tetrahydrofurandimethanol with anacyl halide. It is preferable to carry reaction out in the presence of abasic catalyst such as pyridine and an organic solvent which iscompatible with the reactants such as tetrahydrofuran.

The preferred procedure is as follows: 2,5-tetrahydrofurandimethanol isfirst mixed with pyridine and tetrathe non-aqueous phase, which may besubsequently purified as by degasification and/or distillation underreduced pressure.

The following examples illustrate the preparation of monoesters of HMF:

Example 1 To 50 g. HMF dissolved in 69 g. butyric anhydride was added 3ml. pyridine and the whole heated one hour at -100 C. The excessanhydride was removed by distillation. The product, HFM butyrate, wasthen distilled at a temperature of 79-87" C. and a pressure of 0.060 mm.Hg. The product had a refractive index at 25 C. of 1.5023.

I Cale. Found o 52. 2o 52. 50 Analytical data on semicarbazone H 6. 985. N 10. 60 16. 92

Example 2 The run described in Example 1 was repeated using 56 ml. ofpropionic acid anhydride (56.6 g., 0.436 mol). The crude yield was 100%of red liquid 11 :1.5000; the distilled product, HMF propionate, was apale yellow-green liquid, n =1.5090, B.P.=84-86 C. at 0.1 mm.

Cale. Found C 50. 30 50.54 Analytical data on semicarbazone H 5. 48 5.30N 17.58 17.85

Example 3 To 50 g. (0.396 mol) HMF dissolved in 100 ml. dry

pyridine was added with stirring and cooling, 71.8 g. (0.44 mol) of2-ethyl hexanoyl chloride, also dissolved 3 in 100ml. of dry pyridine.The reaction mixture was aged for 60 minutes at 30 C. and quenched in500 ml. H O. After extraction with ethyl ether, washing, drying anddecolorizing with Nuchar C1000 N, the yield of 4 Example 8 A solution of91.0 g. (0.50 mol) of HMF propionate, produced by the process of Example2, in 700 ml. ethyl ether was hydrogenated over 10 g. Raney nickel at150 dark oil was 98%, n 5 =l.4822. Distillation of a por- 5 h d tion at0.13 mm and C g the Product, 0. and 1000 p.s.1.g. The catalyst wasfiltered, was-e HMF 2 h 1 h 7 b n Th d t h d with methanol, and thesolvent removed.

'g ggg rzgg S pro a The product, 2-hydroxymethyl-5-tetrahydrofurfuryl relac ve m ex a o propionate, weighed 88.4 grams (94%), n :1.447l.Distillation of a portion was accomplished at 92-94" C. l 1 Fmmd (0.080mm n =1.4530, d =1.099 g./ml. and no unexpected absorption by infrared.The analytical data Analyflcaldam onsemmrbazone g ?;2, 3 for 2-hyd xym ty y y -p p V N 13. 59 13.75 low:

16 Example 4 Cale. Found Fifty grarns of HMF (0.396 mol) and 44 g. ofsuc- C 57.45 50.93 cinic anhydride 0.44 mol) were heated in 200 ml. dryAnalyticaldamnsemmbmne H pyridine at 95 C. for 30 minutes. An oilyresidue was formed upon removal of the solvent at mm. Hg pres- Example 9sure. To this was added 75 ml. of 2.5 N I-ICl' and A solution of 40.0 g.(0.202 mol) of HMF butyrate chlnmg S gl of 50nd f as produced in Example1 was hydrogenated at 150 C./ P EF g g d equlvalem Wmg t: 13 1000p.s.i.g. over 3 teaspoons Raney nickel in 300 ml. eory: was Orme 2 ethylether. Removal of catalyst and solvent gave nearly a theoretical yieldof monoester, Z-hydroxymethyl-S- l Calc- Fmmd tetrahydrofurfurylbutyrate, n =1.4463. Distillation C I 17 47 10 at 8591 C./0.150 mm. gavea water white product, Analyticaldamonsemicarbame n H .5 478 n A y i dbased on Y Y N 14.86 14.05 yI-S-tetrahydrofurfuryl butyrate are asfollows:

Example 5 Cale. Found The run described in Example 3 was repeated usingc 59.50 59. 07 adipoyl chloride (34.8 g., 0.19 mol) to yield acrystalline H $98 solid, M.P. 9.l92.5 C., which by analysis was shown to,be the his HMF adipate. Example 10 2 hydroxymethyl 5 tetrahydrofurfuryl(2)- Calc- Fmmd ethylhexanoate was prepared from the corresponding 0 40HMF ester, which was produced by the process of Exmm 50-57 ample 3. 69.0g. (0.274 mol) of HMF-Z-ethylhexanoate Analytlcal data on Semmarbazone"l g Ki 1%: were reduced over 7.5 g. Raney nickel in 500 ml. ethyl etherat 150 C./1000 p:s.i.g. Work-up yielded 96 percent 'of crude2-hydroxymethyhS-tetrahydrofurfuryl-2- Examp e 6 ethylhexanoate, n=1.4512. Distillation of this prody apfocedllre slmllaf to that used 111Example 5, bls uct'at 0.15 mm. '(l09110 C.) yielded'a compoundhavselvacate a p p from HMF and sebacoyl ing a refractive index at 25 c.of 1.4558. Q In 90% y The crude product was a cfys'ial- The followingexamples represent the preparation of 11113 nd, D the monoesters of2,5-tetrahydrofurandimethanol repre- The following examples illustratethe preparation of 50 sented by th f ula; the saturated monoesters of2,5-tetrahydrofurandimetha- 1101 represented by the formula: 8 8

HOCH r CHICO3 CH2 |1CO1CH v CHaOH RCOaCH ,0 011,011 Exam le .11

E l 7 19.0 g. (0.089 mol) of'the acid succinate of HMF, xamp e producedby'the process of Example 4, was hydrogenated HMF acetate may beprepared by the process deover 2.0 g. Raney nickel in 200 ml. methanolat 150 C./ scribed by Karashima, Chemical Abstracts, vol. 23, p. 1000p.s.i.g. Essentially quantitative yields of the prod- 2175. not,2-hydroxymethyl-S-tetrahydrofurfuryl acid succinate, 200 g. of HMFacetate was dissolved in 1600 ml. 'n =1.4550, were-obtained. Afterdistillation, 88-98 of diethylether and 30 g. of Raney nickel catalystwas C. at 0.100 mm., the refractive index showed only a added. Thesolution was hydrogenated at 100 C. at small change, n =1.4539. 200 psi.The catalyst was removed by filtration, and The same product,-2-hydroxymethyl-5-tetrahydrofurthe filtrate was fractionated giving 113g. of pure 2-hyfuryl acid succinate, was prepared by reducing the aciddroxymethyl 5 tetrahydrofurfuryl-acetate. The liquid maleate of HMF inthe same manner as described above. product boiled at 94-98 C. at 0.03mm. and showed a The final product showed a refractive index of 25 C.re'fractiveindex at 25 C. of 1.455. at 1.4534.

Cale. Found Gale. Found Example 12 Cale. Found Example 13 Bis (HMF)sebacate, produced by the process of Example 6, was reduced over Raneynickel at 150 C. at a hydrogen pressure of 1000 p.s.i.g. The crudeproduct, bis (2 hydroxymethyl 5 -tetrahydrofurfury1) sebacate, showed arefractive index at 25 C. of 1.459 8.

Example 14 A -liter spherical glass vessel fitted with a stiner wascharged with the following mixture:

2,5' tetrahydrofurandimethanol gm 1244 Pyridine m 690 Tetrahydrofuran cc2764 A second solution consisting of 2764 cc. of tetrahydrofuran and 700gm. of lauroyl chloride was added to the 10-1iter vessel, dropwise, overa period of 5 hours. The temperature of the reaction mass was maintainedin the range of 10-15" C. After the addition of the second solution, theresulting mixture was maintained at a temperature of 20 C. for a periodof 20 hours, with stirring. The resulting reaction mass was then addedto 12 liters of water containing 300 gm. of sodium chloride. The massthen separated into two phases-upper: nonaqueous, lower: aqueous. Theupper phase was then separated from the lower phase. The upper phase wasthen extracted successively with a solution of 1 M HCl, one volume of 5%NaCl solution, one volume of 5% NaHCO 5% NaCl-90% H 0, and one volume ofa 5% NaCl solution. The upper phase was then dried with anhydrousmagnesium sulfate. After drying, the

upper phase, 2,5 tetrahydrofurandimethanol laurate, Was subjected toreduced pressure, thereby removing volatile impurities. The product hadthe following physical properties:

Specific gravity 0.97 Refractive index at 26 C 1.4580

Example 15 An experiment similar to that can'ied out in Example 14 wasrun with the exception that oleyl chloride rather than lauroyl chloridewas used. Thus,2,5-tetrahydr0- furandimethanol oleate was produced. Ithad the following properties:

Specific gravity 0.95 Refractive index at 26 C 1.4684

Any departure from the above description whichconforms to the presentinvention is intended to be included within the scope of the claims.

What is claimed is:

1. A compound selected from the class consisting of compounds having theformula RCOzHaClQJ-CILOH and HOH20-LOJ-CHaO02(CH2)nCOnCHz-L0JCHg0H whereR is an alkyl radical having from 1 to 18 carbon atoms and n has a valueof 1 to 10.

2. A compound having the formula wherein n has a value of 1 to 10.

3. 2-hydroxymethyl-5-tetrahydrofurfuryl acetate. 4. Bis(Z-hydroxymethyl-S-tetrahydrofurfuryl)-adipate. 5.2-hydroxymethyI-S-tetrahydrofurfuryl oleate. 6. Bis(2-hydroxyrnethy1-5-furfuryl) adipate.

No references cited.

1. A COMPOUND SELECTED FROM THE CLASS CONSISTING OF COMPOUNDS HAVING THEFORMULA